According to official press invitations for Sony's events during the upcoming gamescom conference in Cologne, Germany, Sony has at least two previously unannounced titles to show.
At E3, Sony debuted Beyond: Two Souls and Wonderbook, but left current and potential PlayStation Vita owners scratching their heads. At least one of these two new titles should be a AAA PlayStation Vita exclusive, while the other, is most likely yet another PS3 exclusive.
Being Europe's equivalent to E3, we wouldn't be surprised to see one of Sony's Europe-based studios at the helm of these new titles.
The reveals would almost certainly be announced during Sony's gamecom press conference, which is scheduled for August 14th, at 7PM local time, or 1PM EDT/10AM PDT.
[Source]